{"id":"CVE-2026-98929","title":"macsec: initialize SecY before registering the netdevice","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmacsec: initialize SecY before registering the netdevice\n\nCreating a MACsec device with MAC offload over an LRO-capable lower\ndevice triggers a warning in rtmsg_ifinfo_…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= c09440f7dcb304002dfced8c0fea289eb25f2da0 < 2b42adf3b8ee9a0e1d2629aca3c5a02a1c438066","Linux >= c09440f7dcb304002dfced8c0fea289eb25f2da0 < b07bea42bf590edb0fd507ab25622a74af09548b","Linux >= c09440f7dcb304002dfced8c0fea289eb25f2da0 < c2de369c5c5b8599ca10fd5ca8d11fcd845c1331","Linux 4.6"],"published":"2026-10-23","updated":"2026-10-23","sourceUpdated":"2026-10-23T12:08:11.551Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98929","references":[{"url":"https://git.kernel.org/stable/c/2b42adf3b8ee9a0e1d2629aca3c5a02a1c438066"},{"url":"https://git.kernel.org/stable/c/b07bea42bf590edb0fd507ab25622a74af09548b"},{"url":"https://git.kernel.org/stable/c/c2de369c5c5b8599ca10fd5ca8d11fcd845c1331"}],"tags":["cve.org"],"ingestedAt":"2026-10-23T13:24:55.565Z","slug":"CVE-2026-98929","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmacsec: initialize SecY before registering the netdevice\n\nCreating a MACsec device with MAC offload over an LRO-capable lower\ndevice triggers a warning in rtmsg_ifinfo_build_skb() when IPv4\nforwarding is enabled by default.\n\nregister_netdevice() invokes inetdev_init(), which disables LRO and emits\na NETDEV_FEAT_CHANGE notification. This reaches macsec_fill_info() before\nmacsec_add_dev() initializes the SecY. key_len is still zero, so\nmacsec_fill_info() returns -EMSGSIZE and trips the WARN_ON in\nrtmsg_ifinfo_build_skb(), even though the skb has enough space.\n\nEven without the warning, notifications during registration can report\nuninitialized SecY attributes, including the SCI. This ordering has existed\nsince the driver was introduced.\n\nInitialize the SecY and apply the new-link attributes before registration.\nMove MAC address inheritance into macsec_newlink() so the SCI can also be\ninitialized before registration-time notifications report it. Move the\nper-CPU statistics and metadata destination allocation into ndo_init(),\nand release partial allocations on failure.\n\n## Affected\n\n- `Linux >= c09440f7dcb304002dfced8c0fea289eb25f2da0 < 2b42adf3b8ee9a0e1d2629aca3c5a02a1c438066`\n- `Linux >= c09440f7dcb304002dfced8c0fea289eb25f2da0 < b07bea42bf590edb0fd507ab25622a74af09548b`\n- `Linux >= c09440f7dcb304002dfced8c0fea289eb25f2da0 < c2de369c5c5b8599ca10fd5ca8d11fcd845c1331`\n- `Linux 4.6`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}